Textile twisting unit



March 4, 1941. G. sMiTH TEXTLE TWISTING UNIT INVENTOR @awa/dwz Shi/ ',9

Filed June 17, 1940 Patented Mar. 4, 194i UNITED STATES PATENT OFFICE e2,233,645 f TEXTILE TwIsTING UNIT Connecticut Application June 17, 1940,serIaI No. 340,932

Claims.

An object of the present invention is tov provide a simple and eillcientdouble twisting unit in which the material being twisted is maintained-against rotating with the revolving yarn guide by magnets provided withdamping coils, these magnets being on the mounting means for the packageand being attracted toward pole pieces mounting means, the gap betweenthe pole faces of the magnets and their pole pieces on the fixedmmberjbeing annular and providing limited but suillcient space for ayarn guide to revolve at high speed within the gap.

Another object of the invention is to provide ltensioning means for thematerial being twisted and including guiding means for the material inthe revolving twisting member, ,there being a light spring pressing athin disc against a portion of the revolving member for the materialbeing twisted as it advances from the package to the revolving twistingdisc and its guide to provide a light tension on the material.

And finally it is an 'object of the invention to prevent oscillation orhunting of the package supporting member during operation by providingdamping means in the form of damping poles on the end faces of themagnets by slotting these faces and filling the spaces with highlyconducting and preferably non-magnetic material vsuch as aluminum,brass, copper, etc., of which the package supporting member may be castor other.- wise formed.

With the above and other objects in view the invention includes thefeatures of construction and operation set forth in the followingspeciil- Fig. 1 is an elevation of a complete twisting unit madeaccording to the present invention, parts being broken away to moreclearly show their construction;

Fig. 2 is a horizontal sectional view taken on a fixed unit membersurrounding the package through the supporting member for the yarnpackagerand Fig. 3 is a detail view in elevation of the packagesupporting member showing the face of one of its magnets and the dampingmeans thereon. In the above mentioned drawing there has been shown butone embodiment of the invention which is now deemed preferablabutit isto be understood that changes and modiflcations may be made within thescope of the appended clalms without departing from the spirit of theinvention.

Briefly, and in its preferred aspect, the invention is applicable to atwister including the following principle parts: First. a fixed unitsupport; second, a rotatable member therein on which is mounted a threadguide; thirdfa package support on which may be mounted the materialbeing twisted; fourth, anti-friction bearings sup-V porting this packagesupporting member centrally upon the rotatable member; fth, magnets onsaid package supporting member having their end. faces at spacedportionsof the periphery thereof and having damping coils formedtherein; sixth, pole pieces on the fixed support and adjacent the endfaces respectively of the magnets; seventh, a guiding conduit centrallywithin the package supporting member,l and eighth, a guide for the yarnbeing twistedon the rotatablemember at the periphery thereof and adaptedto rotate within the gap between the periphery of the package supportingmember and the pole pieces.

Referring more in detail to the figures of the drawing, I provide afixed assembly supporting or body member I0. Anumber of these xedmembers may be mounted upon any usual form of twisting machine frame toform twisting units therein and may be retained in fixed positions byany desired means not shown. Rotatable cen- ,Y

I3 one only of which is shown. To permit rotation of the plate Iland-its associated members within the support I0 at high speeds theplate II may be secured to the upper end of a shaft I4. This shaft Ilmay be rotated by any means, not shown, and may preferably be mounted onantifriction bearings I5.

Mounted centrally upon the upper end of the supporting plate Il is apackage or material supporting member I6. As shown in Fig. 1 the plateII has a central member I'I extending upward therefrom and provided withanti-friction bearings I8. On member I6 may be-placed a package ofmaterialto be twisted' such as the cone I9.

Extending centrally upward from the material` supporting member I6 is atubular member 20 around which the cone I9 is centered. I

A continuous guideway is therefore provided for the material beingtwisted from the package I9 through the tube 20- and the members I6 andI'I to a position below the plate lII and thence out through one of thetubular guides I3. Preferably and as shown in Fig. 1 a light tensioningplate or disc 2| is spring pressed upward against a surface of member Ilso that this plate or disc applies a light drag or tension on thematerial being twisted as it is drawn from the twisting unit.

In order to retain the member -16 against rotation while the plate IIand assembled parts are rotating at extremely high speed, magnets 22 areformed, preferablyl by casting, within the member I6 which is ofnon-magnetic but conducting material such as brass, aluminum, etc.

As shown in Fig. 2, two of these magnets 22 are provided each of whichhas its opposite pole or end face at spaced portion of the periphery ofthe member I6 which asshown is circular. On the xed supporting member I0are formed pole pieces 23 there being one pole piece for each pole faceof magnets 22. Preferably the pole pieces may be formed as integralparts of member I0, the magnetic material of Which this member is madebeing -increased at Ythese portions. These pole pieces 23 are spacedslightly from the pole faces of magnets 22 so that an annular but narrowopening is formed about which the guide I3 and the material beingtwisted travels during rotation of the member II. During this rotationof member II the support I6 for the 'material Vbeing twisted is retainedagainst rotation bythe magnetic attraction of the magnetic poles to thepole pieces. v

As the guide I3 rotates at extremely -high speeds and the tension on thematerial may be irregular there is a-tendency for the supporting memberI6 to rotate or swing-back and forth. The only force preventing thismotion is the magnetic attraction between the magnet end faces and thepole pieces 23. When oscillations start effective damping means arerequired to effectively reducev this swinging and restore the member I6lto lrest. Such damping meansare provided by the end faces of vthemagnets 22 being slotted vertically,l thespaces provided by these slotsbeing iilled with a' .metal having good conductingv qualities. As statedabove the member I6 may be .cast of brass, aluminum, etc., in a mouldinto which the magnets 22 have previously been placed. The cast materialtherefore forms damping coils surrounding the end projections of themagnets 22. v

Any tendency of the package supporting meniber I6 to oscillateI or swingback and forth tends to increase and decrease the air gap between the lpoles and their pole pieces 23. This change in air gap will change themagnetic iiux linking the damping coils which in turn will inducecurrents in the coils. These induced currents absorb en- A`ergy from themotion of oscillation and thus speed and the strand of material passes'from the package or supply I9 maintained against rotation by the meansabove/ described through n guide I3. From the guide I3 the strand ofmaterial being twisted passes upward'to a centrally mounted eyelet24.1ixed to a part of the machine and thence to a suitable take-upmechanism.n With each rotation of the plate II and guide I3 By varyingthe -rate of advancing or feeding motion of the strand thestrandreceives two twists.

from the eyelet`24 bythe take-up mechanism the number of twists per unit'of length can be widely4 ing a central rotatably mounted member forsupporting the material beingtwisted and housed centrally withinthetwisting unit, magnets within said material supporting 'member havingtheir vpole ends at the periphery thereof, polepieces within saidtwisting unit, wherebysaid supportingmember is ymaintained in apredetermined rotative position, and damping coils formed at said poleends, whereby movements of said supporting member from said position arerestrained and said position restored.

3. A textile twisting unit comprising in combination, a unit member, amaterial supporting member mounted centrally of said unit mem-v ber,material guiding means rotatable within said unit member and revolvablerelative to said material supporting member, means to guide materialfrom said supporting member to said rotatable guiding member, andmagnets having damping coils at their pole facesto aid in retaining saidsupply support against rotation and for preventing oscillation of saidsupport during operation of said guiding member.

4. A double, twister unit comprising in combination, a fixed unitmember, a material supporting member mounted for rotation therein butnormally retained in a predetermined rotative position duringv thetwisting operation, magnets within one of said members, pole piecesformed in the other member, said magnets and pole pieces cooperating toretain said supporting member against rotation, said magnets havingtheir pole ends slotted, and damping coils extending about said slottedends.

5. A double twister unit comprising in combination, a fixed unit member,a material supporting member of conductingv material mounted forrotation therein but normally retained in a predetermined rotativeposition during the twisting operation, magnets within one of saidmembers, pole pieces formed'in the other member, said magnets'and polepieces cooperating to retain said supporting member against rotation,said magnets having their pole ends slotted, and the conducting materialof said supporting member extending around said slotted ends to formdamping coils thereon.

GRAYDON SMITH.

